Diagnostic test elements are important components of clinically relevant analytical methods. In this connection, the focus is on the measurement of analytes, for example metabolites or substrates, which for example can be determined directly or indirectly with the aid of an enzyme that is specific for the analyte. In this case, the analytes are converted with the aid of an enzyme-coenzyme complex and subsequently quantified. This entails the analyte to be determined being brought into contact with a suitable enzyme, a coenzyme and optionally a mediator, whereby the coenzyme is physicochemically changed, for example oxidized or reduced, by the enzymatic reaction. If a mediator is additionally used, it usually transfers electrons from the reduced coenzyme released during the conversion of the analyte onto an optical indicator or the conductive components of an electrode so that the process can be detected, by way of non-limiting example, photometrically or electrochemically. A calibration provides a direct relationship between the measured value and the concentration of the analyte to be determined.
An important criterion when providing diagnostic test elements is their long-term stability. Certain test elements known from the prior art which are used in the determination of blood glucose are generally very sensitive to moisture and heat, such that upon exposure to the same the function of the coenzyme and mediator, for example, is usually impaired. In certain instances where, for example, tests are carried out by the end user himself, erroneous results can therefore occur due to an incorrect, unnoticed faulty storage of the measurement system which can be hardly detected by the user and may result in incorrect treatment of the respective disease.
Thus, special protective measures are required for the production and storage of conventional diagnostic test elements which prevent contact of the test chemistry of the diagnostic test element with moisture and heat, and in particular with moisture. This can be accomplished by, for example, introducing desiccants, such as silica gel or a molecular sieve, or sealing elements into a storage container containing the test element.
Consequently, such test elements have the disadvantage that they have to be used within a few minutes after removal from the storage container in order to ensure faultless functionality. If it is intended to insert the test element into an analytical measuring device after it has been removed from the storage container or from a primary packaging, the test element must additionally be kept dry until it has been completely used up which requires elaborate apparatus and considerably limits the design of the test element as well as of the analytical measuring device.
One non-limiting object of the present application is to provide a storage container for diagnostic test elements in which the disadvantages of the prior art are at least partially eliminated. In one particular but non-limiting aspect, the ability to store the diagnostic test element in the storage container without elaborate apparatus and over a long period of time in the presence of moisture and/or heat without thereby suffering a significant loss of enzyme activity is desired.